百微米精度的单光子测距

Single-photon detectors based on avalanche photodiodes and time-correlated single-photon counting technology are widely used in pulsed laser ranging. The ranging accuracy is one of the most important performances of laser ranging. In this work, a laser ranging method based on high-precision single-photon detector is developed to achieve laser ranging for non-cooperative targets with hundred-micron-level ranging accuracy. In the system, a low-time jitter Si APD single photon detector, picosecond pulsed laser and high-precision timing counter are used to reduce the time jitter of the ranging system, and a reference position is added to suppress the influence of delay drift of the system. And a laser interferometer system with a ranging resolution of 1 nm and an accuracy of 0.5 ppm is used to calibrate the distance of each movement of the ranging target. The photon flight time accuracy of 0.5 ps is achieved while the integral time ≥ 3 s. The ranging accuracy of 65 μm@RMS is realized, while the target is 2 m away. This work is one of the highest levels of pulsed time-of-flight ranging, and provides an effective technology for high-precision ranging and imaging of long-range non-cooperative targets.